What I was trying to do
At first I thought nothing was happening at all so I tried to exclude problems one by one but at last I noticed that "only" the custom copyright tags hadn't been copied.
This is enough to make basic Special:Upload much better for the use case I had today (uploading three related files/screenshots).
I'm also filing some separate bugs for other components of what seemed a complete failure at first.
Version: master
Severity: normal
Attached: